Packaged Ready to Eat Fresh Food Items and Method of Packaging Fresh Ready to Eat Food Items

Abstract

Packaged food items, such as a fresh, ready to eat salad, comes in a container maintaining a substantially inert, low pressure atmosphere therein. The salad includes a salad dressing positioned lowermost in the container and a lettuce item positioned upper most in the container. Various additional food items are positioned within the container between the salad dressing and the lettuce item. The additional food items include pickled, raw or cooked vegetable items, grain or pasta items, protein items and cheese items. All of the food items are present in different measured proportions depending on the combination of items in the container. The additional food items are layered in a particular order also dependent upon the combination of items present in the container.

Description

FIELD OF THE INVENTION

This invention relates to packaged, fresh, ready to eat foods.

BACKGROUND

While pre-packaged, ready to eat foods are a great convenience, such foods do not necessarily equate to a healthy meal comprising high quality ingredients as these factors are often sacrificed for ease of packaging, shelf life and transport considerations. Furthermore, unless the packaged food is frozen, it has a relatively limited shelf life even when refrigerated. There is clearly an opportunity to provide packaged, fresh, ready to eat foods having an extended shelf life which provide a healthy meal using fresh ingredients of the highest quality.

SUMMARY

In one aspect, the invention concerns a cylindrical container for holding food items. In an example embodiment, the container comprises a cylindrical sidewall surrounding a central space for receiving the food items. The sidewall defines an opening at a first end. A bottom is attached to a second end of the sidewall opposite to the first end. A gas permeable membrane covers the opening and is attached to the sidewall to promote and extend freshness and edible life of the food items. A lid covers the membrane and is removably attached to the sidewall. In a specific example embodiment the sidewall is cylindrical and the opening has a diameter equal to or less than 3.75 inches in diameter.

By way of example, food items within the container may be primarily comprised of fresh, ready to eat vegetables and lettuces. In a further example embodiment, the food items may be primarily comprised of fresh, ready to eat fruits.

In an example embodiment, one or more inert gases are contained within the central space of the container. The inert gases may include carbon dioxide or nitrogen or combinations thereof. Further by way of example, the gases may comprise residual oxygen contained within the central space. In a specific example, the inert gases comprise carbon dioxide over a range from 0% to 40% by volume. In a further example, the inert gases comprise nitrogen over a range from 60% to 100% by volume. Also by way of example, the gases may have a gas content from 0.5% to 20% oxygen by volume. In another example embodiment, the inert gases may comprise 5% oxygen, 18% carbon dioxide and 77% nitrogen by volume.

In an example embodiment of the container according to the invention the gas permeable membrane has a permeability such that equilibrium between the central space and the ambient is achieved within 48 hours of sealing the membrane to the container. Further by way of example, the gas permeable membrane may have a permeability such that the ready to eat food items maintain freshness from 30% to 40% longer than comparable packaged ready to eat food items. In an example embodiment, the gas permeable membrane has a permeability such that the food items maintain freshness for at least 10 days.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of example packaged ready to eat food items according to the invention;

FIG. 2 is an isometric view of example packaged ready to eat food items with the lid removed from the container;

FIG. 3 is a sectional view of example packaged ready to eat food items according to the invention; and

FIG. 4 is a flow chart illustrating an example method of preparing a packaged salad according to the invention.

DETAILED DESCRIPTION

FIGS. 1 and 2 show an example embodiment of packaged, fresh food items, in this example a salad 10 according to the invention. It is understood that the invention is not limited to salads, but is applicable to a wide range of food items, salads being used herein by way of example. The example packaged salad 10 comprises a container 12 and a plurality of food items 14 positioned within a central space defined by the container. Generally, the food items primarily comprise fresh, ready to eat vegetables and lettuces as well as fresh, ready to eat fruits. In this example the plurality of food items 14 includes at least a salad dressing 16 positioned lowermost in the container 12 and a lettuce item 18 positioned uppermost in the container.

The container 12 comprises a gas impermeable sidewall 20 and a bottom 22. It is advantageous to form container 12 from a food grade polymer resin such as polyethylene terephthalate (PET) which is resistant to breaking and can withstand repeated washings and sanitizing processes to allow reuse of the container. Sidewall 20 defines an opening 24 (FIG. 2) oppositely disposed from the bottom. It is thought advantageous that the sidewall be cylindrical and the opening be equal to or less than 3.75 inches in diameter. As further shown in FIG. 2, a membrane 26 is attached to the container overlying and enclosing the opening 24. The membrane comprises a gas permeable barrier film used in modified atmosphere packaging (MAP) and may be formed of materials such as low density polyethylene, polyvinylchloride and polypropylene. Barrier films are appropriate because they can provide decreased permeability to moisture and oxygen and thereby preserve an atmosphere within the container 12 which delays oxidation and inhibits the growth of aerobic spoilage organisms when used with gas flushing techniques associated with modified atmosphere packaging. Membrane 26 advantageously has a permeability such that equilibrium between the central space of the container and the ambient is achieved within 48 hours of sealing the membrane to the container 12. Furthermore, the membrane's permeability is such that the food items maintain freshness form 30% to 40% longer than comparable packaged food items, such that the food items within the container maintain freshness for at least 10 days.

During packaging, an atmosphere of one or more gases is established within the container by drawing a partial vacuum within the container and then flushing the container with the gas or gases, which may be, for example, relatively inert gases such as carbon dioxide, nitrogen and combinations thereof. Residual oxygen may also be within the container 12. Practical atmospheres within the container may comprise carbon dioxide over a range from 0%-40%, nitrogen over a range from 60%-100%, and oxygen over a range from 0.5%-20%. In a specific example embodiment, the atmosphere within the container 12 may comprise 5% oxygen, 18% carbon dioxide and 77% nitrogen. (All ranges are specified as a volume percentage.)

In a practical example, a partial vacuum in a range between about 500 to 975 millibars below standard atmospheric pressure is established within the container (with about −600 millibars being thought advantageous). The container is then flushed with a gas or a mixture of gases comprising about 0% to 40% by volume carbon dioxide and about 60% to 100% by volume nitrogen, with about 30% carbon dioxide and about 70% nitrogen by volume being thought advantageous. The gas flush is conducted at a pressure ranging from about 800 to 1013 millibars below standard atmospheric pressure, with about −950 millibars being thought advantageous. The container 12 is then sealed with the membrane 26 with the gas atmosphere within the container at the sub-atmospheric pressure. In the practical example described above the gas pressure within the container after the container is sealed comprises oxygen over a range from about 5% to 10% by volume, carbon dioxide over a range of about 5% to 40% by volume and nitrogen over a range of about 67% to 95% by volume. Specific gas content of 5% oxygen, 18% carbon dioxide and 77% nitrogen by volume is thought to be advantageous. The packaged salad 10 may further comprise a lid 28 removably attached to the container overlying the opening 24 and protecting the membrane 26. In an example embodiment container 12 comprises a jar wherein opening 24 has substantially the same diameter as the bottom 22. Other types of containers are of course feasible.

The food items comprising the packaged salad 10 are further protected from spoilage by the order in which they are positioned within the container 12. In the example salad, it is advantageous that the dressing 16 be positioned lowermost within contain 12 as shown in FIGS. 1 and 3. Above the dressing 16, a pickled vegetable item 30 may be positioned. Above the pickled vegetable item 30 a grain food item 32 and/or a pasta food item 34 may be positioned. In the next higher layer a raw vegetable item 36 and/or a cooked vegetable item 38 may be positioned. A protein item 40 may be positioned above the cooked/raw vegetable layers 36 and 38 followed by a cheese item 42 positioned beneath the lettuce item 18 which occupies the uppermost position within the container 12. The term “lettuce item” as used herein is meant to cover a broad range of plant items including leaf lettuce, Romaine, Iceberg, Boston, Bibb, kale, arugula, spinach, radicchio, endive and Frisee' as well as various cabbages such as green cabbage, Savoy, red cabbage, Napa, Bok Choi and Brussels Sprouts to cite some examples.

As can be imagined, the number and variety of food items which can form a packaged salad 10 according to the invention leads to a large number of potential salad combinations. As a practical matter however, appetizing salads can be organized (although not limited) into four broad profiles depending on the food items positioned between the salad dressing and the lettuce item. The four example profiles are:

• • I. Vegetable/Grain or Pasta/Cheese;
  • II. Vegetable/Cheese/Protein;
  • III. Vegetable/Protein/Grain or Pasta; and
  • IV. Vegetable/Protein/Grain or Pasta/Cheese.

Research has furthermore shown that there is an optimum relative content of the ingredients for each of these profiles which leads to an appetizing salad which is expected to have a maximum shelf life when refrigerated. The relative content for each salad profile is present below.

I. Vegetable/Grain or Pasta/Cheese

Item	Content Range (% wt)	Favored Value (% wt)
Salad Dressing	12-18	14
Lettuce Item	16-19	18.5
Vegetable Item	8-38	30
Grain/Pasta Item	20-45	26.6
Cheese Item	8-11	10.9

II. Vegetable/Cheese/Protein

Item	Content Range (% wt)	Favored Value (% wt)
Salad Dressing	14-20	19
Lettuce Item	16-19	18.5
Vegetable Item	30-40	38
Protein Item	14-17	16.3
Cheese Item	8-11	8.2

III. Vegetable/Protein/Grain or Pasta

Item	Content Range (% wt)	Favored Value (% wt)
Salad Dressing	14-20	14.7
Lettuce Item	16-19	16.7
Vegetable Item	14-16	14.7
Grain/Pasta Item	30-40	39.2
Protein Item	14-17	14.7

IV. Vegetable/Protein/Grain or Pasta/Cheese

Item	Content Range (% wt)	Favored Value (% wt)
Salad Dressing	14-20	14.5
Lettuce Item	13-17	13.5
Vegetable Item	14-16	16
Grain/Pasta Item	30-40	34
Protein Item	14-17	14
Cheese Item	8-11	8

The invention also encompasses a method of preparing a packaged salad. By way of example, a method of preparing a packaged salad is shown in FIG. 4 and may comprise:

positioning a salad dressing in a gas impermeable container having a bottom and an opening oppositely disposed from the bottom;

• • positioning a lettuce item in the container at a position above the salad dressing;
  • drawing a partial vacuum within the container;
  • flushing the container with one or more gases; and
  • sealing the opening with a membrane (44).

The one or more gases may comprise nitrogen, carbon dioxide and combinations thereof. Advantageously for extended shelf life, the membrane may be a gas permeable membrane. As noted above, in a practical example, the partial vacuum drawn within the container may be from about 500-975 millibars below standard atmospheric pressure, with about −600 millibars thought advantageous. Further by way of example, the gas flush is conducted at a pressure below standard atmospheric over a range of about 800-1013 millibars, with a pressure of about −950 millibars being thought advantageous. The gas flush may comprise carbon dioxide over arrange from about 0% to 40% by volume, and nitrogen over a range from about 60% to 100% by volume. A gas flush mixture of about 30% carbon dioxide and about 70% nitrogen by volume is thought advantageous. After the container is sealed, the gas content of the container may range from about 5% to 10% oxygen by volume, about 5% to 40% carbon dioxide by volume, and about 60% to 95% nitrogen by volume. In a practical example, a gas content of 5% oxygen, 18% carbon dioxide and 77% nitrogen by volume is thought to be advantageous.

An example method according to the invention may further comprise positioning one or more additional food items within the container between the salad dressing and the lettuce item. The additional food items may comprise a pickled vegetable item, a cooked vegetable item, a raw vegetable item, a grain item, a pasta item, a cheese item, a protein item and combinations thereof.

Further by way of example, FIG. 4 illustrates that a method may also include:

• • positioning the cheese item between the lettuce and the cooked vegetable item or the raw vegetable item or the pickled vegetable item (46);
  • positioning the grain item or the pasta item between the raw vegetable item or the cooked vegetable item and the salad dressing (48);
  • positioning the protein item between the cheese item and the cooked vegetable item or the raw vegetable item or the pickled vegetable item (50); and
  • positioning the pickled vegetable item between the grain item or the pasta item and the salad dressing (52).

It is expected that packaged salads 10 according to the invention will provide appetizing meals which, under constant refrigeration, will last for at least 10 days without the formation of undesirable levels of bacteria or significant change in appearance of the contents. Furthermore, the packaging of the container contents, complete and without any intervening packaging or structure internal to the container is expected to contribute to the convenience of use, as preparation of the salad merely requires that the jar be shaken before opening to properly intermingle the contents.

Claims

1. A packaged salad, said packaged salad comprising: a container;a plurality of food items positioned within said container, said plurality of food items including at least a salad dressing positioned lowermost in said container and a lettuce item positioned uppermost in said container.

2. The packaged salad according to claim 1, wherein said plurality of food items further includes a pickled vegetable item positioned between said salad dressing and said lettuce item.

3. The packaged salad according to claim 1, wherein said plurality of food items further includes a grain food item positioned between said salad dressing and said lettuce item.

4. The packaged salad according to claim 1, wherein said plurality of food items further includes a pasta food item positioned between said salad dressing and said lettuce item.

5. The packaged salad according to claim 1, wherein said plurality of food items further includes a raw vegetable item positioned between said salad dressing and said lettuce item.

6. The packaged salad according to claim 1, wherein said plurality of food items further includes a cooked vegetable item positioned between said salad dressing and said lettuce item.

7. The packaged salad according to claim 1, wherein said plurality of food items further includes a protein item positioned between said salad dressing and said lettuce item.

8. The packaged salad according to claim 1, wherein said plurality of food items further includes a cheese item positioned between said salad dressing and said lettuce item.

9. The packaged salad according to claim 1, wherein said container comprises: a gas impermeable sidewall and bottom, said sidewall defining an opening oppositely disposed from said bottom;a membrane attached to said container overlying and enclosing said opening.

10. The packaged salad according to claim 9, wherein said membrane comprises a gas permeable barrier film.

11. The packaged salad according to claim 9, further comprising one or more gases within said container.

12. The packaged salad according to claim 11, wherein said one or more gases are at a pressure below atmospheric pressure.

13. (canceled)

14. (canceled)

15. The packaged salad according to claim 1, further comprising a lid removably attached to said container overlying said opening.

16-85. (canceled)

86. The packaged salad according to claim 11, wherein said one or more gases comprise at least one of carbon dioxide, nitrogen, or oxygen.

87. The packaged salad according to claim 11, wherein said one or more gases comprise carbon dioxide over a range from 0% to 40% by volume.

88. The packaged salad according to claim 11, wherein said one or more gases comprise nitrogen over a range from 60% to 100% by volume.

89. The packaged salad according to claim 11, wherein said one or more gases comprise oxygen over a range from 0.5% to 20% by volume.

90. The packaged salad according to claim 11, wherein said one or more gases comprise 5% oxygen, 18% carbon dioxide and 77% nitrogen by volume.

91. The packaged salad according to claim 10, wherein said container comprises a space in communication with said opening, wherein said gas permeable barrier film has a permeability such that equilibrium between said space within said container and an ambient is achieved within 48 hours of sealing said membrane to said container.

92. The packaged salad according to claim 10, wherein said gas permeable barrier film has a permeability such that said plurality of food items maintain freshness for at least 10 days.